Even if one gives up the concept of God, there are quite a few recognized immaterial things that one has to struggle with. Things such as thought, truth, logic, morality, purpose, and justice become a real problem if the universe is simply material. One could say that these things are imaginary, but then they would have to explain the immaterial construct of imagination. — Joel Furches (from, Christ-Centered Apologetics: Sharing the Gospel with Evidence)